Serum cortisol and thyroid hormone levels in neonates with sepsis

Hypothyroxinemia in sick term neonates and its risk factors in an extramural neonatal intensive care unit: a prospective cohort study

Objective

Thyroid functions in the sick newborns may be altered in the first week of life. Transient hypothyroxinemia has been reported in these babies, which could be due to the immaturity of the hypothalamic-pituitary-thyroid axis or to acute illness. We conducted this study to estimate the incidence of hypothyroxinemia and determine its risk factors in sick term newborns.

Materials and methods

We analyzed free T4 (FT4) and thyroid-stimulating hormone (TSH) levels in sick term neonates (≤7 days of life) admitted to the neonatal intensive care unit. FT4 and TSH levels were estimated in the first week of life in all the enrolled neonates (N = 98) and then repeated at 14-21 days of life in 46 babies. Risk analysis was conducted using univariate and multivariate logistic regression, and numerical data was compared using the Mann-Whitney U test and t-test.

Results

Hypothyroxinemia was seen in 10 (10.2%) of the admitted term babies. Male gender, vaginal delivery, presence of hypoxic ischemic encephalopathy, and need for mechanical ventilation (>24 hours) were identified as risk factors. There was a significant negative linear correlation between FT4 level in the first week of life and duration of hospital stay.

Conclusion

Hypothyroxinemia is common in sick term neonates.

The factors associated with transient hypothyroxinemia of prematurity

Background

Hypothyroxinemia is defined by low levels of thyroxine (T4) despite low or normal levels of thyroid-stimulating hormone (TSH). This study aimed to evaluate the factors associated with transient hypothyroxinemia of prematurity (THOP) in newborns admitted to the neonatal intensive care unit (NICU).

Method

This is a single center, retrospective, case-control study. Premature newborns, between 24 and 34 weeks of gestation, hospitalised between January 2014–December 2019 in Istanbul University-Cerrahpasa Faculty of Medicine NICU were analyzed through their medical records. Thyroid function tests were routinely performed between the 10th and 20th days of postnatal life and were evaluated according to the gestational age references. Thirty six possible associated factors (prenatal and postnatal parameters, medical treatments, clinical diagnoses and applications in NICU) were searched in the patient group with THOP (n = 71) and the control group with euthyroid prematures (n = 73). The factors for THOP were identified by univariate analysis, followed by multivariate analysis.

Results

Mean gestational ages of the study and the control groups were 29.7 ± 2.48 and 30.5 ± 2.30 weeks, respectively (p = 0.606). The birth weight, small for gestational age (SGA), intraventricular hemorrhage (IVH), congenital heart disease (CHD) were found to be the possible associated factors for THOP in the univariate analysis and CHD (p = 0.007, odds ratio [OR]:4.9, 95% confidence interval [CI]: 1.5–15.8), BW (p = 0.004, OR:0.999, 95% CI: 0.9–1.0) and SGA (p = 0.010, OR:4.6, 95% CI: 1.4–14.7) were found to be factors associated with THOP determined by univariate logistic regression analysis.

Conclusıons

Although some treatment practices might have had direct effects on pituitary–thyroid axis, related with the severity of the newborn clinical conditions, non of them was found to be a associated factor for THOP. However, CHD and SGA may be considered as associated factors with THOP detected in preterm infants.

Influence of innate immune activation on endocrine and metabolic pathways in infancy

Prematurity is the leading cause of neonatal morbidity and mortality worldwide. Premature infants often require extended hospital stays, with increased risk of developing infection compared with term infants. A picture is emerging of wide-ranging deleterious consequences resulting from innate immune system activation in the newborn infant. Those who survive infection have been exposed to a stimulus that can impose long-lasting alterations into later life. In this review, we discuss sepsis-driven alterations in integrated neuroendocrine and metabolic pathways and highlight current knowledge gaps in respect of neonatal sepsis. We review established biomarkers for sepsis and extend the discussion to examine emerging findings from human and animal models of neonatal sepsis that propose novel biomarkers for early identification of sepsis. Future research in this area is required to establish a greater understanding of the distinct neonatal signature of early and late-stage infection, to improve diagnosis, curtail inappropriate antibiotic use, and promote precision medicine through a biomarker-guided empirical and adjunctive treatment approach for neonatal sepsis. There is an unmet clinical need to decrease sepsis-induced morbidity in neonates, to limit and prevent adverse consequences in later life and decrease mortality.

Diagnostic Value of Assessment of Serum Cortisol, Hepcidin and Thyroid Hormones Levels in Neonates with Late-Onset Sepsis

Neonatal sepsis is a clinical syndrome characterized by symptoms and signs of infection in the first twenty-eight days of life. Serum thyroid, cortisol and hepcidin are affected by neonatal sepsis. ; Aim of the Work: The aim of this study was to assess the diagnostic value of serum thyroid hormones including free triiodothyronine (free TT3) and free tetraiodothyronine (free TT4), serum cortisol and hepcidin levels through comparison of their concentrations between normal neonates and neonates with high probable late-onset sepsis. ; Patients and Methods: This case-control study was carried out on 40 neonates with suspected high probable late-onset neonatal sepsis based on clinical and laboratory finding who were admitted to NICU of Pediatric Department, Tanta University, Egypt in the period from April 2017 to May 2019 (group I) and 40 healthy neonates matched in age and sex as a control group (group II). For patients and controls, blood culture, highly sensitive C-reactive protein (H-s CRP), serum hepcidin, serum cortisol and thyroid hormones levels including free TT3 and free TT4 were assessed. ; Results: There were no significant differences between studied groups regarding weight, gestational age, sex and mode of delivery. H-s CRP, serum cortisol and hepcidin were significantly higher in group I than group II while serum-free TT3 and free TT4 were significantly lower in group I compared with controls (group II). There was significantly lower H-s CRP, serum hepcidin and cortisol and significantly higher serum-free TT3 and free TT4 in group I after antibiotic therapy compared to the same group before treatment while there were no significant differences between group I after antibiotic therapy and control group (group II) regarding the same parameters. There was a significant positive correlation between H-s CRP and serum hepcidin and cortisol in group I while there was a significant negative correlation between H-s CRP and free TT3 and free TT4. ROC curve of specificity and sensitivity of H-s CRP, serum hepcidin, cortisol, free TT3 and free TT4 in the prediction of neonatal sepsis shows that serum hepcidin had the highest sensitivity and specificity with 95% and 90% respectively followed by serum cortisol, H-s CRP, free TT3 and lastly free TT4. ; Conclusion and Recommendations: Neonates with high probable sepsis had significantly higher serum cortisol and hepcidin and significantly lower free TT3 and free TT4 compared with healthy neonates. These findings may draw our attention about the use of these markers in the diagnosis of neonatal sepsis which can help in early treatment and subsequently better prognosis.

Nonthyroidal Illness Syndrome Across the Ages

In conditions of acute illness, patients present with reduced plasma T3 concentrations without a concomitant rise in TSH. In contrast, plasma concentrations of the inactive hormone rT3 increase, whereas plasma concentrations of T4 remain low-normal. This constellation of changes, referred to as nonthyroidal illness syndrome (NTIS), is present across all ages, from preterm neonates and over-term critically ill infants and children to critically ill adults. Although the severity of illness strongly correlates with the severity of the NTIS phenotype, the causality of this association remains debated, and pathophysiological mechanisms remain incompletely understood. In the acute phase of illness, NTIS appears to be caused predominantly by an increased peripheral inactivation of thyroid hormones, in which reduced nutritional intake plays a role. Current evidence suggests that these acute peripheral changes are part of a beneficial adaptation of the body to reduce expenditure of energy and to activate the innate immune response, which is important for survival. In contrast, in more severely ill and prolonged critically ill patients, an additional central suppression of the thyroid hormone axis alters and further aggravates the NTIS phenotype. Recent studies suggest that this central suppression may not be adaptive. Whether treatment of this central component of NTIS in prolonged critically ill patients, with the use of hypothalamic releasing factors, improves outcome remains to be investigated in large randomized control trials.

Nonthyroidal illness in critically ill children

PURPOSE OF REVIEW

This review summarizes recent literature on nonthyroidal illness syndrome (NTI) and outcome of pediatric critical illness, to provide insight in pathophysiology and therapeutic implications.

RECENT FINDINGS

NTI is typically characterized by lowered triiodothyronine levels without compensatory TSH rise. Although NTI severity is associated with poor outcome of pediatric critical illness, it remains unclear whether this association reflects an adaptive protective response or contributes to poor outcome. Recently, two metabolic interventions that improved outcome also altered NTI in critically ill children. These studies shed new light on the topic, as the results suggested that the peripheral NTI component, with inactivation of thyroid hormone, may represent a beneficial adaptation, whereas the central component, with suppressed TSH-driven thyroid hormone secretion, may be maladaptive. There is currently insufficient evidence for treatment of NTI in children. However, the recent findings raised the hypothesis that reactivation of the central NTI component could offer benefit, which should be tested in RCTs.

SUMMARY

NTI in critically ill children can be modified by metabolic interventions. The peripheral, but not the central, component of NTI may be a beneficial adaptive response. These findings open perspectives for the development of novel strategies to improve outcome of critical illness in children.

Relationships between housing and management factors and clinical health events in elephants in North American zoos

Elephants experience a number of health issues that can contribute to their well-being and survival. In managed populations, housing conditions and management practices can influence individual health, so potential risk factors associated with morbidity or mortality should be identified to ensure the best possible standards of care. The goal of this study was to determine if the number of clinical events experienced could be a useful welfare indicator in zoo elephants, and to determine factors associated with key pathologies. We used an epidemiological approach to investigate how intrinsic (species, sex, age) and extrinsic (housing, management) factors were associated with both the total number of clinical events, and each of the four most prevalent pathology types (gastrointestinal issues, skin lesions, lameness, foot lesions), over a 12-month period. The study included 220 (127 African; 93 Asian) elephants housed at 61 facilities across North America. More than 1100 clinical events were identified. Species and sex differences were apparent in the types of pathology encountered, and unsurprisingly, the number of clinical events was positively correlated with age. Factors relating to housing (percent time with indoor/outdoor choice, space experience inside, number of unique environments an elephant was housed in, percent time on soft substrate) and management (enrichment diversity, spread of feeding opportunities) were also related to the number of clinical events. However, relationships were often counter to our initial hypotheses, highlighting caution in assuming cause and effect from correlational analyses such as these. Other welfare indicators such as serum and fecal glucocorticoids and serum prolactin were also associated with health status, being higher or more variable in individuals with a greater number of events. This approach provides insight into housing and management factors related to the health of these species in zoos, and in some cases, may reflect management changes that have already been made to mitigate existing or anticipated health concerns.

Thyroid Hormone Profile in Children with Sepsis: Does Euthyroid Sick Syndrome Exist?

BACKGROUND:

Alterations in peripheral thyroid hormone metabolism play an eminent role in the development of the euthyroid sick syndrome. Altered solvation may also lead to changes in peripheral thyroid hormones. Data on thyroid hormones in critically ill children remain unclear.

AIM:

This study was aimed to evaluate thyroid hormone profile in children with sepsis as well as to assess the association between thyroid level and sepsis outcome.

METHODS:

An observational cohort study was conducted in 80 children with sepsis from October 2015 to January 2016 in Haji Adam Malik General Hospital. T3 and T4 level were measured on day 1 and after > 72 hours of sepsis diagnosed.

RESULTS:

We recorded length of stay in PICU, patient outcome and analysed the relationship with the chi-square test. Level of T3 and T4 were decreased on day 1 in pediatric sepsis. Of 80 subjects, 57 (71.2%) with low-level T3 and 41 (51.2%) with low T4 were found. The relationship between T3 and T4 level on day 1 with the length of stay were not found (P = 0.500; P = 0.987). There were a significant relationship between level of T3 and T4 with outcome (P = 0.0001; OR 24.706; P = 0.014; OR 3.086). Subject with normal T3 and T4 level had 24 and 3 times life chances compare to lower level.

CONCLUSION:

The Euthyroid Sick Syndrome in children with sepsis does exist. There was a significant relationship between T3 and T4 level on day 1 with patient outcome.

Using newborn screening analytes to identify cases of neonatal sepsis

Neonatal sepsis is associated with high mortality and morbidity, yet challenges with available diagnostic approaches can lead to delays in therapy. Our study assessed whether newborn screening analytes could be utilized to identify associations with neonatal sepsis. We linked a newborn screening registry with health databases to identify cases of sepsis among infants born in Ontario from 2010-2015. Correlations between sepsis and screening analytes were examined within three gestational age groups (early preterm: <34 weeks; late preterm: 34-36 weeks; term: ≥37 weeks), using multivariable logistic regression models. We started with a model containing only clinical factors, then added groups of screening analytes. Among 793,128 infants, 4,794 were diagnosed with sepsis during the neonatal period. Clinical variables alone or in combination with hemoglobin values were not strongly predictive of neonatal sepsis among infants born at term or late preterm. However, model fit improved considerably after adding markers of thyroid and adrenal function, acyl-carnitines, and amino acids. Among infants born at early preterm gestation, neither clinical variables alone nor models incorporating screening analytes adequately predicted neonatal sepsis. The combination of clinical variables and newborn screening analytes may have utility in identifying term or late preterm infants at risk for neonatal sepsis.

Thyroid abnormalities in term infants with fungal sepsis

Objective:

To describe thyroid alterations in term newborns (TNB) with fungal sepsis during NICU hospitalization.

Method:

The study included six TNB that during the clinical and laboratory manifestations of sepsis with positive cultures for fungus showed changes in thyroid hormones, called low T3 syndrome and low T3-T4 syndrome. TNB that could present hormonal changes caused by disease as those born to mothers with thyroid disease, or who had perinatal asphyxia and major surgeries were excluded.

Results:

Of six TNB with fungal sepsis, five had positive culture for Candida albicans and one had positive culture for Candida tropicalis. Low T3 syndrome was observed in two TNB (50%), while T3-T4 syndrome was observed in other two (100%). The four children progressed to septic shock.

Conclusion:

Fungal sepsis is becoming more common among newborns admitted to NICU. Thyroid insufficiency could be a marker of disease severity with possible need for hormone supplementation.

Maternal factors and complications of preterm birth associated with neonatal thyroid stimulating hormone

Thyroid hormones are important regulators of fetal neurodevelopment. Among preterm infants, thyroid stimulating hormone (TSH) is highly variable. Understanding this variability will further improvements in screening for thyroid disorders in preterm infants. We examined 61 maternal and infant clinical and demographic factors for associations with neonatal TSH levels in 698 preterm neonates. TSH was measured as part of routine State-mandated newborn screening in Iowa. Of the maternal characteristics, nulliparous women (p=8×10-4), women with preeclampsia (p=2×10-3), and those with induced labor (p=3×10-3) had infants with higher TSH levels. TSH levels at the time of newborn screening were associated with respiratory distress syndrome (RDS) (p<0.0001) and sepsis (p=3×10-3). We replicated findings between parity and preeclampsia previously observed in primarily term infants. We also observed strong relationships between neonatal TSH and complications of prematurity including RDS and sepsis, which have implications for future studies examining this relationship both prenatally and longitudinally after birth.

The role of interleukin-6 and C-reactive protein in non-thyroidal illness in premature infants followed in neonatal intensive care unit

OBJECTIVE

To investigate the role of interleukin-6 (IL-6) and C-reactive protein (CRP) in non-thyroidal illness (NTI) in premature infants.

METHODS

Serum levels of IL-6 and CRP, thyroid-stimulating hormone (TSH), total thyroxine (T4), free T4 (fT4), total triiodothyronine (T3), and free T3 (fT3) were determined at the 1st, 2nd and 4th weeks of postnatal life in 148 premature infants born before 33 weeks of gestation.

RESULTS

At the 1st week, serum T3 was negatively correlated with IL-6 (r= -0.33, p= 0.001) and CRP (r= -0.17, p= 0.03). Serum T3 was negatively and more strongly correlated with IL-6 (r= -0.49, p= 0.001) and CRP (r=- 0.33, p= 0.03) at the 2nd week, at which time sepsis frequency and low T3 rates were the highest. At the 4th week, mortality rate was higher among infants with lower T3 levels.

CONCLUSIONS

High IL-6 and CRP values related to neonatal sepsis might have a significant role in the pathogenesis of NTI in premature infants.

Serum thyroid hormones levels are significantly decreased in septic neonates with poor outcome

The aim of this prospective study was to investigate the effects of thyroid hormone levels on the sepsis criteria and mortality in septic newborns. This study was performed at the Firat University Hospital Neonatal Intensive Care Unit. A group of septic newborns and a control group of healthy non-infected newborns were evaluated. Blood samples were obtained at onset from septic and healthy newborns and at 10th day of the antibiotic therapy from only septic newborns, and thereafter serum total T(3) (TT(3)), total T(4) (TT(4)), and TSH levels were determined. A total of 292 newborns were included in the study. Serum TT(3) levels at onset and at 10th day of the antibiotic therapy were 163.8±63.4 and 178.3±33.1 ng/dl, TT(4) levels were 6.9±2.2 and 11.0±2.6 mg/ml, and TSH levels were 3.8±2.1 and 4.0±2.5 μU/ml, respectively in septic newborns. Serum TT3 levels were 180.3±47.6 ng/dl, TT(4) levels were 10.9±2.3 mg/ml, and TSH levels were 4.1±2.2 μU/ml in healthy newborns. Serum TT(3), TT(4) levels of septic newborns were significantly decreased with respect to those of healthy newborns at onset and serum TT(4) levels was increased significantly after antibiotic therapy. To the best of our knowledge, this report is the first study to compare thyroid hormone levels in a large number of septic newborns and a healthy group. Our findings suggest that before and after treatment of neonatal sepsis a significant change is realized in thyroid hormone levels.

Thyroid profile of term appropriate for gestational age neonates in Nigeria: a forerunner to screening for congenital hypothyroidism

Thyroid hormones in normal quantity are vital for physical growth and mental development during fetal and postnatal life. The available publications in Sub-Saharan Africa on the thyroid function of newborn infants was reported in babies delivered in moderate to severe goitre zones; utilizing the hormone levels from these studies may have a measure of bias. Newborn screening for congenital hypothyroidism (CH) in Sub-Saharan Africa is still a mirage, the technicality of the best timing for collection of blood samples need to be studied. Consequently, we report the serum levels of total thyroxine (T4), triiodothyronine (T3) and thyroid stimulating hormone (TSH) at birth and at 72 h after birth, and to ascertain if there is any significant difference between them. This was a prospective cross-sectional study (6 months period) between November and April 2005. One hundred and fourteen apparently healthy term AGA neonates had their thyroid function analyzed, the females (59) were slightly more in number than the (males 55). Most of them were between GA of 37-38 weeks at birth. The observed 72 h mean values of serum T3 and T4 (1.06 and 101.38 nmol l(-1)) compared with the cord values at birth (0.89 and 75.48 nmol l(-1)), was not statistically significant. The mean cord TSH levels (13.59 mU l(-1)) compared with 72 h serum TSH levels (10.25 mU l(-1)) was also insignificant p = 0.3. For Sub-Saharan Africa cord TSH analysis may be a reasonable choice for newborn screening for congenital hypothyroidism.

Pathophysiology and treatment of septic shock in neonates

Neonatal septic shock is a devastating condition associated with high morbidity and mortality. Definitions for the sepsis continuum and treatment algorithms specific for premature neonates are needed to improve studies of septic shock and assess benefit from clinical interventions. Unique features of the immature immune system and pathophysiologic responses to sepsis, particularly those of extremely preterm infants, necessitate that clinical trials consider them as a separate group. Keen clinical suspicion and knowledge of risk factors will help to identify those neonates at greatest risk for development of septic shock. Genomic and proteomic approaches, particularly those that use very small sample volumes, will increase our understanding of the pathophysiology and direct the development of novel agents for prevention and treatment of severe sepsis and shock in the neonate. Although at present antimicrobial therapy and supportive care remain the foundation of treatment, in the future immunomodulatory agents are likely to improve outcomes for this vulnerable population.

Nonthyroidal illness syndrome and euthyroid sick syndrome in intensive care patients

This article reviews the pathophysiology of non-thyroidal illness syndrome (NTIS) and euthyroid sick syndrome (ESS), a multifactorial phenomenon characterized by suppression of thyroid hormone levels that has been described in several disease states, probably due to different causes in different patients. It also describes the laboratory values of thyroid function tests (TFTs), relevant animal studies, the association of NTIS and ESS with cardiovascular problems and sepsis, and the rationale for treatment.